Sunday, March 30, 2014

Reverse total shoulder: complications, reoperations and the learning curve

These authors reviewed 112 patients who underwent 114 RSA procedures, 93 were primary arthroplasties and 21 were revisions. Of the primaries, 73 were for cuff deficiency/cuff tear arthropathy, 20 were for fracture.

The total complication rate for the entire group was 7%; the reoperation rate was 5.3%. Complications included 3 periprosthetic fractures, 3 hematomas, 1 acromion fracture, and 1 deep infection.

The complication rates was 4.3% for the primaries and 19% for the revisions.

The The complication rate was 19% in the revision RSA group and 4.3% in the primary RSA group.

The reoperation rate was 2.2% for the primaries and 19% for the revisions.

Comment: Interestingly there were no reported instances of instability (the authors were cautious in the progression of activities after the surgery, careful to try to repair the subscapularis, and committed to a design that laterializes the center of rotation creating East/West tensioning - factors that may help minimize the risk of instability).

The surgeon's technique included minimal humeral reaming and cementing, rather than attempting a press fit through greater reaming - an approach that may have minimized the rate of intraoperative fracture. The surgeon used only hand reaming of the glenoid - an approach that may help preserve valuable glenoid bone stock.

While the authors did not find evidence of a learning curve related to surgical experience in this series, these surgeries were performed by a surgeon with a reverse total shoulder volume of over 20 cases/year - perhaps the learning curve had been successfully negotiated prior to the start of this series.

Finally, the average followup was 26 months (range 12-48). In that the risk of certain of the complications - e.g. periprosthetic fractures, scapular fracture, infection - continue for the life of the patient, it may be more meaningful to say that the annualized complication rate was just over 3% per year.